For Cancer Immunotherapy Patients, a ‘One-Two Punch’ Could Hold Promise

(DGIwire) – Immunotherapy, in which the human immune system is harnessed to treat cancer, has shown great promise but relatively few patients have responded significantly. Among strategies to enhance its power, one of the most intriguing involves so-called “combination” therapies—a “one-two punch” in which immunotherapy is administered along with another type of therapeutic. In recent years, researchers have identified several compounds that not only kill cancer but selectively attack tumor cells while leaving normal cells alone. According to a recent article in R&D magazine, encouraging data for two drugs being studied by Rexahn Pharmaceuticals—RX-3117 and RX-5902—could prove useful in these combination therapies. Rexahn is currently recruiting patients for clinical studies to see how its compounds work in metastatic pancreatic cancer and triple negative breast cancer.

“RX-3117 (for metastatic pancreatic cancer and advanced bladder cancer) and RX-5902 (for triple negative breast cancer) are designed to inhibit specific biological pathways that are present in cancer cells and are involved in the growth and spread of tumors,” says Douglas J. Swirsky, President and CEO of Rexahn. “We are now progressing to study these agents as alternatives to the current standard of care in patients who are newly diagnosed with metastatic cancer.”

According to Mr. Swirsky, there are solid scientific reasons behind the push to try Rexahn’s compounds in combination with immunotherapy. For example, RX-5902 has shown an ability to decrease a specific protein that is associated with shutting down the body’s natural tumor immunity. By inhibiting this protein, RX-5902 improves the ability of the immune system to kill tumor cells and enhances the effectiveness of the immunotherapeutic approach. As for RX-3117, this compound kills tumor cells and exposes antigens—substances that trigger an immune response—to tumor-killing immune cells, so it may also have the ability to increase the effectiveness of immunotherapy.

There is a reason why Rexahn has chosen to pursue the particular forms of cancer it is focusing on. For RX-3117, the company is focusing on pancreatic and bladder cancer because drugs with a similar mechanism of action have worked well in those tumor types and there is a very well-defined pathway to approval in the United States. Because this compound is targeted to tumor cells, the company hopes to see a greater level of effectiveness and a prolonged response in patients.

Meanwhile, with RX-5902, Rexahn has progressed development in triple negative breast cancer because it is associated with activation of the biological pathway targeted by RX-5902. Also, according to Mr. Swirsky, there is currently no drug approved for this form of cancer, so there may be a faster regulatory route to approval if it is shown to be an effective treatment.

“We believe there is great promise in pursuing the combination therapy approach—and based on results obtained to date, we are optimistic about how our compounds might one day help advance the state of care,” Mr. Swirsky adds.